[填空题]
A 4.2-m-diameter merrypy-yycv lk0,,ecq 71y-go-round is o1fgc hg b)c 1up0d(yi89ww (zrotating freely with an angular velocity of 0.8ow(0p)i9bgc11(dg8w zyf u ch $rad/s$ Its total moment of inertia is 1760 $kg \cdot m^2$ Four people standing on the ground, each of mass 65 kg, suddenly step onto the edge of the merry-go-round. What is the angular velocity of the merry-go-round now? $rad/s$ What if the people were on it initially and then jumped off in a radial direction (relative to the merry-go-round)? $rad/s$